The primary objective of this research will be to establish permanent lymphocyte cell lines from selected strains of mice and rats. Cultures will be initiated from animal peripheral blood, lymph nodes and bone marrow. Cellular components will be separated by various means. Growth stimulation will be attempted using a variety of agents. Factors in the culture environment which influence establishment and the normalcy of lines established shall be determined. Tumors will be induced and tumor lines established in culture. Lymphocyte-tumor cell reactions will be studied; inhibitors in the interaction will be investigated, as well as the production and use of antilymphocyte globulin.